1. Field of Invention
The invention relates to a subtitle position detection and modification method and device, in particular, to the method and device of subtitle position detection and modification according to an active display area of displaying device.
2. Related Art
The species, stability, capacity, application and playing device of storage medium evolving into variety since the technology progressing and the higher demand of quality of audio and video. For example, the digital versatile disc (DVD) applies MPEG compression technique to create high quality dynamic image, and provides the sub picture/subtitle mechanism for the purpose of improving interaction between the digital contents and the audience. Moreover, the sub picture/subtitle file includes many subtitles and menus so that the DVD may support at most 32 subtitle streams, and the digital content provider can design various menus, tags, auxiliaries for aurally handicapped person auxiliary, simple animation, and subtitles supporting multi-languages mode.
In practice, the source of video, audio, and sub picture/subtitle file encoded by corresponding encoder respectively, and then mixed up to form a DVD image file stored in a DVD disc, whereas the playing system decodes corresponding encoded data stream and then forwards to a displaying device such as a television. FIG. 1 is a schematic block diagram of the playing procedures of a DVD player according to the prior art, herein a data stream separating unit 110 of the playing system separates MPEG video data stream, audio data stream, and sub picture data stream from the source data stream of the data source 100, and then decoding them by corresponding decoder respectively. For instance, the MPEG video data stream is decoded by a MPEG decoder 120, the audio data stream is decoded by an AC-3 decoder 130, and the sub picture data stream is decoded by a sub picture decoder 140. Hence the decoded MPEG video data stream and sub picture data stream are mixed up by a mixer 150 and converted by a first D/A converter 160 to generate a video output to the playing unit 180, whereas the decoded audio data stream is converted by a second D/A converter 170 to generate a audio output to the playing unit 180.
The subtitle file includes the bitmap format subtitle data and subtitle control signal, and the DVD player reading and decoding the subtitle file from the data source 100 to obtain the bitmap format subtitle data, binding it with image duly to display in the preset subtitle displaying position depends on the corresponding parameters, such as time and position, and then generating and transmitting the frames within subtitles to the display device.
However, the subtitles or parts of them may not adapt to the active display area of the displaying device which is probably caused by improper arrangement of subtitle during DVD producing process, and it will affect the delights of audience, increase the inconvenience, and so much as decrease the quality of the frame. It is therefore a subjective of the invention to provide the subtitle position detection and modification method and device as a solution of improper subtitle display position arrangement, but also eliminate the inconvenience of the complicated adjusting operations and improve vision qualities and feelings of user.